JavaScript has a simplified C-like syntax and is tightly
integrated with the browser Document Object Model. It is
useful for implementing enhanced forms, simple web
databasefront-ends, and navigation enhancements. It is
unusual in that the scope of variables extends throughout
the function in which they are declared rather than the
smallest enclosing block as in C.

JavaScript originated from Netscape and, for a time, only
their products supported it. Microsoft now supports a
work-alike which they call JScript. The resulting
inconsistencies make it difficult to write JavaScript that
behaves the same in all browsers. This could be attributed to
the slow progress of JavaScript through the standards bodies.

JavaScript runs "100x" slower than C, as it is purely
interpreted (Java runs "10x" slower than C code).
Netscape and allies say JavaScript is an "open standard" in
an effort to keep Microsoft from monopolising web software
as they have desktop software. Netscape and Sun have
co-operated to enable Java and JavaScript to exchange
messages and data.